RandomFaceSelect
Takes any Editable Mesh or Editable Poly - collapses it - and then randomly selects faces based on a weight or percentage value.
For a max 5 - 4.2 version of this script - please download bspack_r4_r5_v031.zip. Use the original bspack_r42.zip if you want only max 4.2 compatibility.
The only major differences between script packages are slight version compatibility issues - there are no new scripts added between the 3 packages.